This project will analyze the life-cycle development of the burden of chronic diseases in six 5-year birth-cohorts that reached age 65 between 1885 and 1915. It will seek to identify patterns in the timing of the onset of specific chronic diseases, in the development of co-morbidities, in the changing severity of disease burdens over the life cycle, and in the relationship of patterns of disease burdens to causes of death. The project will also seek to identify risk factors during developmental, young adult, and middle age that affected both the development of the burden of diseases after age 50 and longevity. Special attention will be paid to the life-cycle burden of chronic disease among Union Army (UA) veterans who survived to extreme ages, defined for this population as the longest-lived 10% (age 87 or over), 5% (age 90 or over), and 1% (age 95 or over). The age of onset, the duration, the severity, and the prevalence of chronic disease burdens among Union Army cohorts will be compared with those of the WWI, WWII, Korean War and other cohorts that turned 65 from the mid-1950s on.